Olympic silver medallist Michael Jamieson has not been included in the Great Britain team for this summer's World Championships in Kazan, Russia.
The Scotsman, who reached the podium in the 200m breaststroke in London 2012, finished sixth in his event at the British Championships in London recently.
Meanwhile, Adam Peaty, who set a new world record in the 100m breaststroke at the London Aquatics Centre, leads the 30-strong squad.
On the women's side, Jazz Carlin eased her way through qualification by winning three freestyle golds in the pool almost a fortnight ago, while Commonwealth gold medallists Siobhan-Marie O'Connor and Hannah Miley have also made the squad.
GB team for World Championships:
James Guy (Millfield), Chris Walker-Hebborn, Adam Peaty (City of Derby), Roberto Pavoni, Jazz Carlin, Siobhan-Marie O'Connor, Hannah Miley (Garioch), Elizabeth Simmonds, Thomas Laxton (Loughborough University), Calum Jarvis, Ross Murdoch (University of Stirling), Robbie Renwick (University of Stirling), Nick Grainger (City of Sheffield), Andrew Willis, Aimee Willmott (London Aquatic Centre PP), Eleanor Faulkner (City of Sheffield), Rebecca Turner (City of Sheffield), Sophie Taylor (London Aquatic Centre PP), Rachael Kelly (NC Loughborough), Fran Halsall, Ben Proud (Plymouth Leander), Duncan Scott (University of Stirling), Lauren Quigley (Stockport Metro), Stephen Milne (Perth City), Dan Wallace (Warrender), Liam Tancock, Adam Barrett, Jessica Thielmann (University of Florida), Molly Renshaw, Jemma Lowe